A developing device includes a developer roller to rotate in a rotation direction, a photosensitive body adjacent the developer roller, and an air flow passage extending through a non-image forming region at a longitudinal end of the developer roller. A closest position is defined where the developer roller and a photosensitive body are closest to one another. The air flow passage extends from inside the developing device and forms an air flow directed toward an upstream side of the closest position, relative to the rotation direction of the developer roller.

A developing device includes a developer roller to rotate in a rotation direction, a photosensitive body adjacent the developer roller, and an air flow passage extending through a non-image forming region at a longitudinal end of the developer roller. A closest position is defined where the developer roller and a photosensitive body are closest to one another. The air flow passage extends from inside the developing device and forms an air flow directed toward an upstream side of the closest position, relative to the rotation direction of the developer roller.

A carrier for electrostatic image development includes: a core material; and a coating resin layer that contains inorganic particles and covers the core material. The content of the inorganic particles is 10% by mass or more and 60% by mass or less based on the total mass of the coating resin layer. The volume average diameter D (μm) of the inorganic particles and the thickness T (μm) of the coating resin layer satisfy the following relational expression (1): 0.007≤D/T≤0.24.

Disclosed are methods and systems for solid phase transfer of a reagent to a substrate. In some embodiments, the method comprises providing at least a first composition comprising a solid phase, wherein the solid phase comprises a reagent; and dispensing a first sample from the first composition onto a first coordinate on a substrate, whereby the first reagent is transferred to the substrate from the solid phase.

A developing device includes a developer roller to rotate in a rotation direction, a photosensitive body adjacent the developer roller, and an air flow passage extending through a non-image forming region at a longitudinal end of the developer roller. A closest position is defined where the developer roller and a photosensitive body are closest to one another. The air flow passage extends from inside the developing device and forms an air flow directed toward an upstream side of the closest position, relative to the rotation direction of the developer roller.

A developer includes a metallic pigment and a binder resin. The developer includes a fine powder having a particle size smaller than a mode value in a volume particle size distribution of the metallic pigment. A proportion of the fine powder relative to the developer is equal to or higher than 4.6 percent and equal to or lower than 9.6 percent.

Provided is an electrophotographic photosensitive member in which the generation of a positive ghost image is suppressed under a low-temperature and low-humidity environment, and the occurrence of cracking is suppressed under a high-temperature and high-humidity environment. Also provided are a process cartridge mounted with the electrophotographic photosensitive member, and an electrophotographic apparatus including the process cartridge. The electrophotographic photosensitive member of the present disclosure is characterized in that an undercoat layer contains aluminum oxide particles and titanium oxide particles at a specific mass ratio.

An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m.sup.2. The toner satisfies a relation 0.13≤X/Dn≤0.16, where X [μm] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00×10.sup.−4 N at a loading rate of 3.0×10.sup.−5 N/sec under an environment of 32 degrees C. and 40% RH, and Dn [μm] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.

The present invention relates to a carrier core material for electrophotographic developer, having a ferrite composition and having a supernatant transmittance of 85.0% or more, a method for producing the carrier core material, a carrier for electrophotographic developer, containing the carrier core material, and a developer containing the carrier.

A carrier for forming an electrophotographic image is provided. The carrier includes a core particle comprising a manganese-based ferrite particle having an apparent density of from 2.0 to 2.2 g/cm.sup.3 and a magnetization of from 44 to 52 emu/g in a magnetic field of 500 Oe; and a coating layer coating a surface of the core particle. The coating layer contains a carbon black, an inorganic particle A, and an inorganic particle B. The inorganic particle A and the carbon black each have a concentration gradient in a thickness direction of the coating layer. A concentration of the inorganic particle A increases toward a surface of the coating layer, and a concentration of the carbon black decreases toward the surface of the coating layer.